Supported metal acetylide catalyst



menu Apr. is, 1948 SUPPORTED METAL AOETYLIDE CATALYST Joseph FredericWalker, Westfleld, N. J., and Thomas Edward Londergan, Niagara Falls, N.Y assis'nors to E. I. du Pont de Nemours & Company, Wilmington, DeL, acorporation of No Drawing.

Original application October 30,

1944, Serial No. 561.150. Divided and this application October 31, 1946,Serial No. 707,046

This invention relates to a catalyst material, and more particularly itrelates to a new and improved catalyst material comprising a metalacetylide on a catalyst support. This is a division of our abandonedoopending application Serial No. 561,150, filed October 30, 1944.

U. S. Patent No. 2,232,867 to Reppe et al., discloses the preparation ofa catalyst material comprising a metal acetylide on a catalyst supportand its use in the production of alkinols. The catalyst materialdisclosed in this patent is, however, very unsatisfactory in view of itshigh susceptibility to detonation by either mechanical shock or flame.

It is an object of this invention to produce a catalyst materialcomprising a metal acetylide on a catalyst support which has a lowsusceptibility to detonation by mechanical shock or flame.

It is another object of this invention to provide a method for theproduction of a catalyst material comprising a metal acetylide on acatalyst support which has a low susceptibility to detonation bymechanical shock or e.

It is a specific object of this invention to produce a catalyst materialcomprising a copper acetylide on a catalyst support which issubstantially unsusceptible to detonation by mechanical shoclr or Otherobjects of the invention will appear hereinafter.

The objects of this invention are accomplished, in general, by producinga catalyst material comprising very flnely divided particles of acatalyst support containing, uniformly distributed in the mass of saidparticles, a metal acetylide, said catalyst material containing not toexceed 20% by weight of said metal acetylide.

The above-said catalyst material can be produced by thoro hly mixingfinely divided particles of a catalyst support with an aqueous 'solutionof a metal salt and precipitating the metal acetylide from said metalsalt solution by passing acetylene thmugh said mixture. The quantity ofmetal acetylide precipitated -in the mass of particles of catalystsupport must not exceed 20 by weight, of the final dry catalystmaterial. To still further lessen the detonation hazard of the catalyst.or in some cases completely eliminate the detonation by meclmnical shockor flame, it is 2 essential that the particles of catalyst support havea size not to exceed 300 mesh.

The present invention contemplates, broadly, the production of any metalacetylide catalyst material; however it particularly contemplatescatalysts taken from the group consistmg of copper acetylide, silveracetylide, gold acetylide and mercurous mercury acetylide. Theacetylides of this group, when dry, are explosive in nature, and thepresent invention provides a highly important process for the productionof catalyst material containing these acetylides which catalyst materialwill have high efilciency and a low susceptibility to detonation.Furthermore, this particular group of catalysts have excellent utilityin the catalytic production of alkinols as disclosed in theabove-mentioned Reppe et a1. patent. The invention will hereinafter belargely described and illustrated with particular reference to copperacetylide. It is to be understood, however, that such specificdescription is equally applicable to the other explosive metalacetylide's; silver acetylide, gold acetylide and mercurous mercuryacetylide.

As a catalyst support, the present invention contemplates the use of anyof the well-known inert materials used as a support or carrier forcatalysts. Such catalyst supports include, for example, animal charcoal,glowed wood charcoal, active carbon, infusorial earth, fuller-"s earth,silica gel, active alumina, Carborundum, and the like. It has beenfound, in accordance with this invention, that the particle size of thesupport is critical and very important. When used for supportingexplosive metal acetylides, the particle size of the catalyst supportwill determine, to a large extent, the explosiveness of the catalystmaterial. In order to obtain a satisfactorily eflective catalyst it isnecessary that the particle size of the support be 300 mesh or finer.meant, of course, that the particles will pass through a screen having300 meshes per linear inch. The following table discloses the detonativeproperties of a number of dry catalyst masses comprising copperacetylide precipitated on a number of different catalyst supporls ofdifferent particle sizes. In each case the catalyst material or masscomprises a ratio of copper acetylide to support of 1:5. The sensitivityto mechanical shack w s determined y tapping the same with By "300 mesh"is I a hammer, and the sensitivity to flame was deter-' mined by passingthe same on a line screen over The metal acetylide should be uniformlydistributed throughout the mass of the catalyst support. It iswell knownthat metal acetylides can be precipitated from metal salt solutions, forexample aqueous solutions of copper chloride, copper phosphate, copperacetate, ammoniacal copper sulfate, ammoniacal copper chloride,silvernitrate, mercurous acetate, ammoniacal goldsodium'thiosulphate, bypassing acetylene through such solutions. In order that the metalacetylide be uniformly distributed throughout the support, the finelydivided support should be thoroughly mixed with the metal salt solutionbefore the metal acetylide is precipitated. Preferably, the mixture isagitated during precipitation. Mixing precipitated metal acetylide withthe finely divided support does not give equivalent results since theresultant catal'ystmaterial contains agglomerated, discreteparticles ofacetylide which are sensitive to mechanical shock or heat and may causeserious explosions.

The catalyst material must contain at least four parts of supportmaterial for each part metal acetylide to produce a catalyst materialwhich is not'subject to serious explosion. In view of the greaterexplosive character of silver acetylide, it is preferred that thecatalyst material contain at least ten parts of support material foreach part silver acetylide. Catalyst material containing mixtures ofsilver acetylide with the other metal acetylides are preferably preparedwith such ratio of support to acetylide as is proportional to themixtures, in accordance copper sulfate (CuSorfiHsOLih 800 cc. of waterand adding 240 cc. of 28% aqua ammonia to this solution. The coppersolution was then reduced by dissolving 192 grams of hydroxylaminehydrochloride and 120 grams of powdered (300 or flner mesh) activecarbon were slowly stirred in with cooling. Acetylene was bubbledthrough the resultant suspension with agitation for about thirtyminutes. The catalyst was removed from the soluton by filtration andwashed well with water. The moist catalystwas then washed with acetoneand vacuum dried. The dry product presented the appearance of a uniformblack powder on examination under the microscope. It did not explode onbeing subjected to mechanical shock or flame. 0n ignition, it burned inexactly the same manner as the active carbon employed in itspreparation. The ratio of support to copper acetylide in the final drycatalyst material was approximately 5 to 1.

Example II Catalysts were prepared by the procedure described in ExampleI but 300 or finer mesh fullers earth and 300 mesh or finer infusorialearth were substituted for the carbon support. The catalysts obtainedwere not sensitive to flame or mechanical shock.

Example III York Central Building, New York, N. Y., and

Example IV Supported gold acetylide catalyst was prepared by dissolving0.4'! gram of sodium gold thiosulfate (equivalent to 0.2 gram of goldacetylide) in 40 ml. of water, adding 10 ml. aqua amwith the aboveguides. The correct ratio of support to acetylide can be obtained bymixing such proportion of metal salt solution and catalyst support aswill produce the desired ratio upon 'completing the precipitation of theacetylide.

In some instances, it has been found thatnonexplosive catalyst materialcan be made with precipitated gold and mercury acetylide containing ashigh as 35% acetylide, based on the total weight of the catalystmaterial. For pur- Example I An ammoniacal copper sulfate solution wasmonia (28% NHa), mixing with 0.4 gram of Nuchar GFO, and bubblingacetylene through the mixture for one hour. The resulting catalyst,containing 32.1% gold acetylide by analysis, was insensitive tomechanical shock or flame although gold acetylide, prepared in anidentical manner without the support, was detonated readily with shockor flame. A similar safe catalyst was prepared which contained 4;0 partsof Nuchar GFO to 1.0 part of gold acetylide, and this catalyst isrecommended to provide a satisfactory margin of safety.

Example V Mercury acetylide was prepared by suspending 2.5 gramsmercurous acetate. equivalent to 2.0 grams mercury acetylide, and 4.0grams of Nuchar GFO in 100 ml. of water and bubbling acetylene throughthe suspension for 25-30 hours with agitation. Light was excluded duringthe reaction. The resulting supported catalyst was insensitive to shockor flame. A mixture containing 4.0 parts Nuchar GFO to 1.0 part mercuryacetylide is recommended to provide a satisfactory margin of safety.

The catalyst material of the present invention prepared by dissolving79.2 grams of will have a very low susceptibility to detonation bymechanical shock, or when subjected to heat acetylene reactions, theirnon-explosive character has marked advantages over previously knownmetal acetylide catalysts. After use in acetylene reactions, thecatalysts of this invention are still active and still insensitive toshock or flame.

Since it is obvious that many changes and modifications can be made inthe above-described details without departing from the nature and spiritof this invention, it is to be understood that the invention is not tobe limited to the abovesaid details except as set forth in the appendedclaims.

What is claimed is:

1. A copper acetylide catalyst material consisting essentially ofparticles of a catalyst support having a size not to exceed 300 meshand,

uniformly distributed therein, said copper acetylide, said catalystmaterial containing not to exceed 20% by weight of said copperacetylide.

2. A silver acetylide catalyst material consisting essentially ofparticles or a catalyst support having a size not to exceed 300 meshand, uniformly distributed therein, said silver acetylide, said catalystmaterial containing not to exceed 10% by weight of said silveracetylide.

3. A metal acetylide catalyst material consist ing essentially of amassof finely divided particles of a catalyst support having a size not toexceed 300 mesh and, uniformly distributed therein, a heavy metalacetylideselected from the group consisting of the acetylides of copper,silver, gold, and mercurous mercury, said catalyst material containingnot to exceed 10% by weight of said acetylide when said acetylide issilver acetylide, and not to exceed 20% by weight of said acetylide whensaid acetylide is the acetylide of copper, gold or mercury.

JOSEPH FREDERIC WALKER. THOMAS EDWARD LONDERGAN.

REFERENCES CITED UNITED STATES PATENTS Name Date

